In most industrialized populations, the major cause of morbidity and mortality in diabetes is atherosclerotic macrovascular disease. Atherosclerosis in the diabetic occurs earlier and is more extensive than in the non-diabetic person. The purpose of this study is to determine the degree and relative susceptibility of diabetic LDL to oxidative modification. Furthermore, since activated PMN, monocytes and macrophages have the ability to oxidatively modify LDL, the effect of diabetic and control cells on the oxidative modification of LDL will also be compared.